Blends of urea-formaldehyde resins and sulfonated thiourea-formaldehyde resins, and method of making and using same



BLENDS OF UREA-FORMALDEHYDE RESINS AND SULFONATED THIOUREA FORMALDEHYDERESINS, AND METHOD OF MAKING AND US- ING SAME William F. Herbes,Bridgewater Township, Somerset County, N.J., assignor to AmericanCyanamid Company, New York, N.Y., a corporation of Maine No Drawing.Application December 2, 1957 Serial No. 699,900

9 Claims. (Cl. 260-103) The present invention relates to stable,water-soluble, hydrophilic, potentially thermosettingresinouscompositions containing a urea-formaldehyde condensate and athiourea-formaldehyde condensate, and more particularly to physicalblends possessed of superior properties composed of partiallypolymerized, partially alkylated, watersoluble urea-aldehydecondensates, and bisulfite-modified, partially polymerized,water-soluble thiourea-formaldehyde condensates, in which thesecomponents are present in certain critical ratios. Further, thisinvention relates to the process for preparing such resins and to theiruse for imparting flame-resistant durable finishes, which aresubstantially free from dusting or flaking, when properly applied andcured to textile materials, and in particular nylon textile materials.

Heretofore, urea-formaldehyde and thiourea-formaldehyde condensates havebeen proposed as textile treating agents, as have mixtures of thesematerials, either employed alone or in conjunction with othercomponents, such as, for example, melamine-formaldehyde condensates and/or certain cyclic ureas, as for example, ethylene urea, 1,2-propyleneurea and their formaldehyde condensates and alkylated derivatives. Stillfurther, it has been disclosed that certain of these resinouscomponents, either alone or in combination with others of the classmentioned hereinabove, may be modified, as for example, with ratherlarge amounts of metalbisulfite to produce resinous compositionspossessed of utility in textile finishing.

Many of these compositions, while possessing certain desirableadvantages, suifer rather significant or important deficiencies, whichin one manner or another limits their utility. Thus, for example,textile finishing compositions of the prior art have, in many instances,been possessed of extremely limited stability, i.e. they hydrophobed orseparated out crystalline material at standard stabilitytest-temperatures very shortly after preparation. Such a characteristiclimits the utility of the resinous material in that in many cases itcould not be shipped to the finisher, because of the limited time ofstability, and many finishing mills are not equipped to prepare suchresinous mixtures.

In the case of bisulfite-modified resinous finishes, the degree ofpolymerization present in such a mixture prepared by a one-pot processand the presence of rather large amounts of combined bisulfite therein,while resulting in acceptable stiifening, when cured properly,

notable discoloration of white goods has been en' countered, thusgreatly limiting the utility of such resin.

Still further, such bisulfite-modified resinous materials have beenproduced which possess satisfactory stability, will impart desirablestiifness and flame resistance to the treated fabric, and in particularto nylon, but suffer from the deficiency that when applied to the nylonin amounts sufiicient to impart the properties of stiflness and flameretardance, do, when cured, result in dusting or flaking when thetreated fabric is subsequently subjected to mechanical action such asthe type encountered in the han- United States Patent preparedseparately.

2 dling of goods after cure, including necessary operations byconverters.

Accordingly, ,it is an object of the present invention to prepare astable, water-soluble, hydrophilic, potentially thermosetting resinouscomposition suitable for use as a textile finishing agent, possessed of'good stability, and which, when properly cured on textile fabrics, andin particular nylon textile material, imparts a durable, stiff handthereto, as well as flame resistance.

It is a further object of the present invention to provide such aresinous composition which, when applied and properly cured, does notproduce significant undesirable discoloration of the finished textilematerial.

It is a further object of the present invention to provide such aresinous composition which, when properly applied and cured as on nylontextile material, in addition to having the other desirable attributesset forth hereinabove, is substantially free from dusting or flakingwhen the fabric so treated is subjected to subsequent mechanical action.

These and other objects and advantages of this invention will becomeapparent from the detailed description set forth hereinbelow.

According to the present invention, a stable hydrophilic, potentiallythermosetting resinous product is provided, which comprises a physicalblend' of a partially polymerized, partially alkylated, water-solubleurea-aldehyde condensate and a partially polymerized, water-soluble,bisulfite-modified thiourea-formaldehyde condensate containing in partsby weight'of the blend 55 to 88 parts of the alkylated urea-aldehydecondensate and from between 45 and 12 parts of the bisulfite-modifiedthioureaformaldehyde condensate.

The partially polymerized, partially alkylated, watersolubleurea-aldehyde component of the blend is prepared by reacting in aqueousmedium relative proportions of from between 1.50 and 2.25 moles of awatersoluble aliphatic aldehyde with l moleof urea at a pH of frombetween 7 and 10, at a temperature of from between 70 and 100 C. for aperiod of time from between .25 and 2.0 hours.

Preferably, the aldehyde-urea condensation is carried out in thepresence of between 0.3 and 2.0 moles of an aliphatic alcohol containingfrom 1 to 3 carbon atoms. While it has been determined that this is notan essential condition, during this stage of preparation of the ureacomponent, the presence of the alcohol in the reaction medium functionsto eliminate the presence of excess water in the reaction medium, whichinhibits condensation.

After condensation with the aldehyde, the pH of the reaction mixture isadjusted to from between 4 and 6 with a suitable acid, as for example,oxalic acid, formic acid or other suitable acids well known to thoseskilled in the art, and if alcohol is not already present it is added inan amount equal to from between 0.3 and 2.0 moles per mole of urea.Thereafter, the urea-aldehyde condensate is alkylated at a temperatureof from between 70 and 100. C. for from .25 to 2.0 hours, after whichthe resulting syrup is neutralized by the addition of caustic or othersuitable neutralizing agent.

The partially polymerized, bisulfite-modified thioureaformaldehydecomponent of the present invention is It is. one ofthe importantfeatures of .the present process that the constituents be in the finalcomposition'in a purely physical association, and that the components ofthe product be prepared separately. Subsequently, it has been found thatwhen the final composition is a physical blend, as opposed to a onepotprocess product, certain apparently inherent characteristics whichrender the one-pot" process final product more diificult to cure andthus adversely affect coloration on a finished nylon material, as wellas dusting or flaking of the resin finish from the treated textilematerial, are avoided.

By the use of the term one-pot process, as employed herein, it is meanta process in which all of the components of the final composition areadded to a given reaction kettle, either simultaneously or in stages,without withdrawals or separation from said vessels, prior to theformation of the final product. By way of example, if in the process ofthis invention, after the alkylation of the urea-aldehyde component thethiourea component was added and then reacted in the presence of theurea component, such would be termed a onepot process.

In the preparation of the alkylated urea-aldehyde component, it ispreferred to employ relative proportions of from 1.9 to 2.1 moles offormaldehyde with 1 mole of urea at a temperature of from between 90 and100 C. at a pH of from between 7.5apd 9 for from .25 to .75 hour. Duringalkylation, it is preferred to alkylate and also partially polymerize ata pH of from between 4.8 and 5.2 and at a temperature of from 90 to 100C. for from 0.5 to 1.0 hour reaction time. Thereafter, the reactionmixture is neutralized, as by the addition of sodium 11ydroxide or othersuitable alkaline material, to a pH of between 7 and 8, and is cooled toless than about 40 C. and preferably to room temperature.

The alkylation of the urea-aldehyde condensate is normally carried outuntil the reaction product has a viscosity of between 3000 and 6000 andpreferably from about 4500-5500 centipoises at 25 C. It has beendeterimned that in carrying out the reaction employing the conditionsand times set forth hereinabove, a reaction product being possessed ofsuch viscosity characteristics is produced.

In the preparation of the bisulfite-modified thioureaformaldehydecomponent, preferably relative proportions of between 0.75 and 1.0 moleof formaldehyde, .02 and .04 mole of a suitable, water-soluble bisulfiteor sulfite capable of rendering bisulfite under the resin-formingconditions of this invention, and 1 mole of thiourea are reacted at a pHof between 7.5 and 9 and at a temperature of from between 80 and 100 C.for from 1 to minutes. Thereafter, the partially polymerized reactionmixture, which is a clear syrup, is cooled to less than about 40 C. andpreferably to room temperature.

As noted hereinabove, these two essential components of the presentinvention are then blended to provide a composition containing in 100parts of blend from between 55 and 88 parts by weight, based on resinsolids, of the partially polymerized, partially alkylated, watersolubleurea-aldehyde reaction product and from between 45 and 12 of thebisulfite-modified, partially polymerized, water-solublethiourea-formaldehyde condensate. Preferably, these components areblended in relative amounts of from between 65 and about 80% of theurea-aldehyde component and from between about 35 and 20% of thesulfite-modified thiourea-formaldehyde component.

The final composition has a visosity from between about 500 and 850centipoises at 25 C., containing in 100 parts of blend from between 20and 35% of the thiourea condensate and optimumly from between 24 and 30%thereof, and from between 65 and 80% of the urea condensate andoptimumly from between 70 and 76%.

The final blend may then be clarified, as through a pressure filter, andis a clear, stable solution, which remains clear and free fromhydrophobing at 12 C. for a time period greater than two months, willremain free from crystallization at 25 C. for at least three months,andwill remain free from crystallization at 37 C. for at least onemonth. Further, the resinous blend prepared in accordance with thepresent invention will not hydrophobe when diluted with 3 parts of waterat 20 '4 C. after three months of storage at temperatures of 25 C. andbelow.

The aldehyde employed in preparing the urea and thiourea condensates inaccordance with the present invention may be selected from a widevariety of watersoluble aliphatic aldehydes capable of producingwatersoluble components when employed under the reaction conditions ofthe present invention. These include formaldehyde, acetaldehyde,propionaldehyde, glyoxal and the like. For purposes of the presentprocess, formaldehyde, either as formalin solution or in its moreconcentrated form, such as paraformaldehyde, is preferred.Paraformaldehyde, as a concentrated form of formaldehyde, is greatlypreferred in the present process in that it eliminates the requirementfor the removal of substantiabamounts of excess Water from the finalproduct, and it is specifically desirable in the preparation of thealkylated urea-formaldehyde component in that the presence of largeamounts of water appears to impede the alkylation of this component.

The alcohol employed in alkylating the urea-formaldehyde component is analiphatic alcohol containing from 1 to 3 carbon atoms. Thus, forexample, methyl, ethyl, propyl and isopropyl alcohol or mixtures thereofare the alcohols contemplated by the present invention. Of these, methylalcohol is greatly preferred in that the solubility and stabilitycharacteristics of the final resinous component are more easilyregulated and enhanced.

The bisulfite modification of the thiourea-formaldehyde component ispreferably achieved by the employment of water-soluble alkali metalbisulfites, as for example, sodium, potassium, lithium, and the like,bisulfite, although sulfite which yield bisulfites under theresin-forming contions of the present invention or mixtres of these twomaterials may obviously be employed. Preferably, the bisulfite is addedas sodium bisulfite or sodium metabisulfite, which readily hydrolyzesunder the conditions of the present process to yield 2 moles of sodiumbisulfite.

The partially alkylated and preferably partially methylated, partiallypolymerized urea-formaldehyde component employed in the blend of thepresent invention is water soluble and is composed of monomeric materialand low order polymeric material, as for example, dimers, trimers,tetrimers, pentamers, and the like. The degree of polymerizationimparted by the processing in accordance with the present invention ofthis component, while producing these low order polymers, results in aproduct which is a soluble, stable, clear solution, and one which willnot hydrophobe when diluted with 3 parts of water at 20 C. after 3months of storage at temperatures of 25 C. and below. On a monomericbasis, this material contains from between about 1.5 to 2 moles ofcombined formaldehyde and from between about 0.1 and about .8 mole ofcombined alcohol, preferably methanol.

The partially polymerized, bisulfite-modified thioureaformaldehydecomponent is water soluble and stable, and is composed of monomer and alow order of polymers of slightly lower order of magnitude than that ofthe alkylated urea-formaldehyde component. This component, on amonomeric basis, contains to between about .7 and about 1.0 mole offormaldehyde per mole of thiourea and between about .01 and about .035mole of bisulfite per mole of thiourea.

it is a principal feature of the present invention that the blendprepared in the above-described manner and of the above-describedcomposition, when properly applied and cured to texile material, and inparticular to nylon material, and preferably nylon net fabrics, im partsa durable, stiff finish thereto, which is flame resistant or which doesnot increase the combustibility of the nylon netting and is free fromdusting or flaking when the finished fabric is subjected to mechanicalaction.

Nylon nettings, such as nylon Rachelle net, may be treated with theresin blend of the present invention by applying it thereto, as bypad-bath, spraying, immersion or other suitable application techniques,in amounts of from between about 1 and.70% solids, based on-the weightof the fabric, and preferably from between about 30 and 65% solids,based on the weight of the cloth. Thereafter, the treated. fabric iscured, as for example, from 5 minutes .at 250 F. to five seconds at 450F. and preferably from 90'sec'onds at 290 to 60 seconds at350 F. to aWater-insoluble state in the presence of acid-curing catalysts 'such asammonium bromide, ammonium chloride, certain mixed isopropanolaminehydrochlorides and the like, to impart a finish having the qualitiesdescribed above. Suitable catalysts of the type referred to above andothers well known to those skilled in the art may be employed in amountsof between .50 and 1 /2 to based on the weight of the resin solids, andpreferably in amounts from between 0.50 and 1%.

In orderto illustrate the present invention, the following examples aregiven byway of illustration, in order that said invention may be morefully understood. No details therein should be construed as limitationson the present invention, except as they appear in the appended claims.All parts and percentagesare by weight unless otherwise designated.

EXAMPLE 1 crystals dissolved in 30 parts of water. Refluxing of thismixture was continued until the viscosity of the syrup was between 5000and 5500 centipoises at 25 C. This required about 45 rninutes-aftertheacid addition.- Thereafter, the pH was adjusted to above 7 with sodiumhydroxide and the batch cooled to 40 C.

Into a three-necked flask equipped as in' jExample 1(A), there arecharged 636parts.,(7.85.moles) of 37% formaldehyde containingapproximately 7% methanol. The pH of this'mixture was adjusted to 9.0with sodium hydroxide and 54 parts (1.64 moles) of 9l%' parafor'maL.

dehyde, 30 parts (0.28 mole) of sodium 'bi'su'lfite and 728 parts (9.48moles) of thiourea wereadded. The mixture was heated to the reflux (96C.:) and cooled immediately to 40 C. or below. The preparation of thiscomponent after all of the reactants were included in the reactionvessel required 90 minutes.

A IOO-part blend in accordance with the present invention was thenprepared by blending 70 parts -by-weight of Example 1(A) which contained80% of active ingredients, with 30 parts by weight of Example 1(B)containing 70% active ingredients. The blended product was a clear,water-white stable syrup containingabout 76% of active ingredients.

EXAMPLE 2.

Nylon marquisette was immersed in a bath containing 80 parts by Weightof the blend. prepared in Example 1(C), 0.48 part by weight of ammoniumchloride as catalyst and 19.52 parts by weight of water.. Afterimmersion for a time sutficient to permit complete penetration of themarquisette fabric, the treated netting was passed'through a' squeezeroll to impart a wet pick-up of about 80%, after which the fabricwas-dried and cured for l'minute at 310 This treated fabric, containing.

48% of the resin solids, based on the dry weight ofthe fabric, had adesirably smooth, stiff finish, substantially freeof discoloration andtendency to dust off "under mechanical action. The treated, fabric wasfound to safely meet the standards described in the Flammable FabricsAct .(P.A.'88-83rd Congress) even after being laundered, whereas asimilar piece of nylon netting, treated with a conventionalthermosetting textile resin (a methylated methylol melamine orcommercial methylated urea-formaldehyde condensate) was classified as afabric subject to rapid and intense burning.

EXAMPLE 3 Into a suitable reaction vessel equipped as in Example 1(A)there are charged 160 parts (5.0 moles) of methanol, 30 parts of 5-Nsodium hydroxide and 396 parts (12.0 moles) of 91% para-formaldehyde.After heating to 70 to 80 C. to depolymerize and dissolve theparaformaldehyde, the pH was adjusted to 8.9. 360 parts (6.0 moles) ofurea were then added and the charge heated to the reflux (96? C.) whereit was held for 30 minutes. After the addition of 3.0 parts of oxalicacid crystals to bring the pH of the reaction mixture down to 4.9, thereflux was continued for an additional 30 minutes. The pH was thenbrought to above 7.0 with sodium hydroxide and the charge cooled toabout 40 C. a

To a reaction vessel equipped as in Example 3(A), there were charged 256parts (3.16 moles) of 37% formaldehyde (7%. methanol) at a pH of 9, 14parts (0.13 mole) of sodium bisulfite and 240, parts (3.16 moles) ofthiourea.

A blend in accordance'with the present invention was then made byphysically mixing 2 parts of the product prepared in Example 3(A) aboveand 1 part of the product prepared in Example 3(B). .This blendcontained 69.5% of the partially polymerized, partially methylatedurea-formaldehyde condensate on an active ingredients or solids basisand 31.5% of the bisulfitemodified thiourea-formaldehyde component on asolids or active ingredient basis. The resulting syrup, which was stableand water soluble, was then applied to nylon marquisette netting, as inExample Z'hereinabove and the resulting fabric was fire resistant andthe finish was durable and substantially free from dustingor flaking offwhen subjected to mechanical action. The treated nylon fabric wassomewhat less stifl or gave a less stiff hand than that fabric treatedwith the blend prepared in accordance withExample 1(C) hereinabove, butwas that the 'acid reflux (methylation) period was extended from 30minutes to 45 minutes.

The partially polymerized, bisulfite-modified thioureaformaldehydecomponent was prepared by substantially the same procedure employed inExample 3(B) above.

The components prepared in Examples 4(A) and 4(B) hereinabove wereblended in a manner and in a propor- The charge was then heated to thereflux, held at reflux for 10 minutes, and cooled to about tion similarto that of Example 3(C) hereinabove. Upon application of the product tonylon marquisette netting in a manner. similar to that described inExample 2, the treated or finished fabric was possessed of properties ofsubstantially the same character, with the exception that the finishimparted was not quite as stiff as that produced in Example 2, but wasnoticeably stiffer than that provided by the blend prepared in Example3(C).

EXAMPLE 5 The procedures of Examples v4(A) and (B) were followed withthe exception that no sodium bisulfite was employed to modify thethiourea component prepared in Example 4(B). Hydrophobing of thiscomponent took place at about 80 C. while heating it to the reflux.

EXAMPLE 6 The procedure of Example 5 was followed, except that thethiourea-formaldehyde component was heated to only 60 C. Employing thistechnique, this component did not hydrophobe, but the final blend becameturbid after one month at 12 C. It is believed that the formation ofthis turbidity under these conditions is predicated on the lack ofpolymerization in this componet of the reaction mixture. Thus, itappears necessary that some polymerization is essential to preventturbidity of the blend during storage. Thus, in contrast, the resinousblends prepared in accordance with Example 4 remained completely clearafter more than 2 months storage at 12 C.

EXAMPLE 7 The partially methylated, partially polymerized, watersolubleurea-formaldehyde component and the partially polymerized, water-solublebisulfite-modified thiourea formaldehyde component were prepared in amanner similar to that employed in Examples 1(A) and 1(3)- hereinabove.

25 parts by weight of the preparation of .1(B) containing 70% solidswere blended with 75 parts by weight of the component prepared inExample 1(A) containing 80% solids. Application of this blend inaccordance with the procedure described in Example 2 resulted in theimpartation of a durable, stiff finish to the fabric and one which wasfree from undesirable flaking or dusting as the result of mechanicalaction, but the flame retardancy was reduced, rendering the blend lessdesirable for commercial usage.

EXAMPLE 8 A blend was prepared in accordance with Example 7 (that is,employing the partially polymerized, partially methylatedurea-formaldehyde component of Example 1(A) and the partially,polymerized, bisulfite-modified thiourea-formaldehyde component ofExample 1(8)) except that 40 parts by weight of the product of Example1(B) containing 70% active ingredients or solids and 60 parts by weightof the product of Example 1(A) containing 80% active ingredients orsolids was prepared. This blend was applied to nylon marquisette nettingin accordance with the procedure outlined in Example 2. The treatedfabric possessed the necessary degree of flame retardancy, wassubstantially free fromdusting or flaking as a result of mechanicalaction, but thehand of the treated fabric was noticeably softer thanthat achieved in Example 7. Since it is a necessary attribute of thepresent resin blend to impart a durable, desirable stitf hand, thisresinous blend was considered unacceptable for commercial usage.

The urea condensates prepared in accordance with the above-describedprocedures and employable in the present invention and the thioureacondensate employable therein typically analyze as. follows:

Urea condensate Percent Moles Ure 38.2 1. 00 Total HOHO 37.7 1.97 FreeHGHO.. 3.7 0.19 Combined HCHO 34.0 1. 78 Methylol HCHO 11.2 0. 59 Totalmethanol 17. 4 0. 86 5. 9 0. 29 11. 5 0. 57

T hiourea condensate Percent Moles Thiourea 49. 9 1. 00 Total HCHO 17. 60. 89 Free HCHO 1. 0 0.05 00 "nbined ECHO" 16. 6 0.84 Methylol HOHO 18.2 0.92 NaHSO; 2. 6 0.036

while the analysis fora typical blend containing 70% of the ureacondensate and 30% of the thiourea condensate is as follows:

Blend Percent Moles Methylol HO HO 13. 3 0.99 Total methanol 12. 2 0.Free me 4. 1 0.30 Combined methanol 8. 1 0.55 NaHsO 0.8 0.017

As has been pointed out, the products of the present invention areparticularly useful and applicable in the field of textile treating, andmore specifically in the field of nylon finishing, wherein frequently inthe case of white goods, as for example the type employed in eveningdress nettings, petticoats and the like, it is desirable that the fabrichas a stiff, flame-resistant, nondusting finish. However, the resinousblend of the present invention may be employed for other purposes, asfor example, in the paper industry, as a chemical intermediate, and thelike.

While the use of the resinous blend of this invention has been describedprimarily in conjunction with the finishing of formed nylon fabrics, itshould be understood that fibers, yarns' or fabrics of nylon alone or inblends with synthetic or natural fibers are contemplated. Such blendsshould contain at least 50% nylon in combination with such materials ascotton, linen, wool, regenerated cellulose, such as viscose rayon andcuprammonium rayon, cellulose acetate, acrylic fibers, polyester fibers,and the like.

I claim:

1. A process for preparing a stable, hydrophilic, potentiallythermosetting resinous product comprising a physical blend of apartially polymerized, partially alkylated, water-soluble urea-aldehydecondensate and a bisulfite-modified, partially polymerized,water-soluble thiourea-formaldehyde condensate containing in parts byweight of the blend 55 to 88 parts of the former and 45 to 12 parts ofthe latter, which comprises reacting in aqueous medium relativeproportions of 1.50 to 2.25 moles of a water-soluble aliphatic aldehydewith 1 mole of urea at a pH of from 7 to 10 and at a temperature of from70 to 100 C. for from'.25 to 2 hours, adjusting the pH of the reactionmixture to a value between 4.0 and 6.0, and reacting said urea-aldehydecondensate to a temperature of between 70 and 100 C. for from .25 to 2.0hours with from 0.3 to 2.0 moles of an aliphatic alcoholcontaining from1 to 3 carbon atoms, and there- -9 after neutralizing the reactionmixture, and reacting in aqueous medium relative proportions of .4 to1.4 moles of formaldehyde, 0.1 to 0.6 mole of a material selected fromthe group consisting of a water-soluble bisulfite and sulfites capableof yielding bisulfites under the conditions to be described, and 1 moleof thiourea at a pH value between 7.0 and 10.0 and at a temperature offrom between 50 and 100 C. for from 1 to 30 minutes, and thereafterblending these respective components in the weight ratios set forthabove.

2. A process according to claim 1 wherein the formaldehyde, thebisulfite and the thiourea are reacted at a temperature of from between80 and 100 C. for from 1 to minutes, and wherein the amount ofwater-soluble bisulfite is from between .02 and .04 mole per mole ofthiourea.

3. A process according to claim 1 wherein the physical blend contains in100 parts by weight thereof 65 to 80 parts of the partially alkylatedurea-formaldehyde condensate and 35 to 20 parts of thebisulfite-modified thiourea-formaldehyde condensate. v

4. A process according to claim 1 in which the alkylated urea-aldehydecondensate is a methylated ureaformaldehyde condensate.

5. A process according to claim 1 in which the urea and aldehyde arecondensed in the presence of an aliphatic alcohol containing from 1 to 3carbon atoms.

6. A process for preparing a stable, hydrophilic, potentiallythermosetting resinous product comprising a physical blend of apartially polymerized, partially methylated, water-solubleurea-formaldehyde condensate and a bisulfite-modified, partiallypolymerized, water-soluble thiourea-formaldehyde condensate containingin 100 parts by weight of the blend 55 to 88 parts of the former and 45to 12 parts of the latter, which comprises reacting in aqueous mediumrelative proportions of between 1.9 and 2.1 moles of formaldehyde with 1mole of urea at a pH of from 7.5 to 9.0 and at a temperature of frombetween 90 and 100 C. for from between .25 and .75 hour, adjusting thepH of the reaction mixture to between 4.8 and 5.2, and reacting saidurea-formaldehyde condensate at a temperature of from between 90 and 100C. for from .5 to 1 hour, with between 0.7 and 1.0 mole of methylalcohol, and thereafter neutralizing the reaction mixture and reactingin aqueous medium relative proportions of between 0.75 and 1.0 mole offormaldehyde and from between .02 and .04 mole of sodium bisulfite and 1mole of thiourea at a pH between 7.5 and 9, and at a temperature ofbetween 80 and 100 C. for from 1 to 5 minutes, and blending theserespective components in the weight ratio set forth above.

7. A stable, hydrophilic, potentially thermosettmg resinous productcomprising a physical blend of a partially polymerized, partiallyalkylated, water-soluble urea-aldehyde condensate and a partiallypolymerized, water-soluble bisulfite-modified thiourea-formaldehydecondensate containing in 100 parts by weight of the blend 55 to 8 8parts of the former and 45 to 20 parts of the latter, said alkylatedurea-aldehyde component being prepared by reacting in aqueous mediumrelative proportions of 1.50

to 2.25 moles of a water-soluble aliphatic aldehyde with 1 mole of ureaat a pH of from 7.0 to 10.0 and at a temperature of from 70 to 100 C.for from .25 to 2.0 hours, adjusting the pH of the reaction mixture to apH of between 4.0 and 6.0, and reacting said urea-aldehyde condensate ata temperature of 70 to 100 C. for from .25 to 2.0 hours, with 0.3 to 2.0moles of an aliphatic alcohol containing from 1 to 3 carbon atoms, andthereafter neutralizing the reaction mixture, said bisulfite-modifiedthiourea component being prepared by reacting in aqueous medium relativeproportions of 0.4 to 1.4 molesof formaldehyde, .01 to .06 mole of amaterial selected from the group consisting of water-soluble bisulfiteand sulfites capable of yielding such bisulfite under the conditions tobe described and 1 mole of thiourea, at a pH range of from 7.0 to 10.0and a temperature of from between and 100 C. for from 1 to 30 minutes,and thereafter blending these respective components in the weight ratioset forth above.

8. A stable, hydrophilic, potentially thermosetting resinous productcomprising a physical blend of a partially polymerized, partiallymethylated, water-soluble ureaformaldehyde condensate and a partiallypolymerized, water-soluble, bisulfite-modified thiourea-formaldehydecondensate containing in 100 parts by weight of the blend to parts ofthe former and 35 to 20 parts of the latter, which comprises reactingrelative proportions of between 1.9 to 2.1 moles of formaldehyde with 1mole of urea at a pH of from 7.5 to 9.0 and at a temperature of frombetween to C. for from between .25 and .75 hour, adjusting the pH of thereaction mixture to between 4.8 and 5.2, and reacting saidurea-formaldehyde condensate at a temperature of from between 90 and 100C. for from .5 to 1 hour, with between 0.7 and 1.0 mole of methylalcohol, and thereafter neutralizing the reaction mixture and reactingin aqueous medium relative proportions of between 0.75 and 1.0 mole offormaldehyde and from between .02 and .04 mole of sodium bisulfite and 1mole of thiourea at a pH between 7.5 and 9, and at a temperature ofbetween 80 and 100 C. for from 1 to 5 minutes, and blending theserespective components in the weight ratio set forth above.

9. A process for treating nylon to impart a durable, stifi hand andflame-resistant finish thereto, which finish is substantially free fromdusting when the fabric is subjected to mechanical action, comprisingtreating said nylon with from between 30 and 65% resin solids of theproduct defined in claim 7 and thereafter curing said resin for from 90seconds at 290 F. to 60 seconds at 310 F. to a waterinsoluble state inthe presence of from between 0.50 and 1% catalyst, based on the weightof the resin solids.

References Cited in the file of this patent UNITED STATES PATENTS2,062,171 Fuchs Nov. 24, 1936 2,582,840 Maxwell Jan. 15, 1952 FOREIGNPATENTS 836,798 France Ian. 25,- 1939

7. A STABLE, HYDROPHILIC, POTENTIALLY THERMOSETTING RESINOUS PRODUCTCOMPRISING A PHYSICAL BLEND OF A PARTIALLY POLYMERIZED, PARTIALLYALKYLATED, WATER-SOLUBLE UREA-ALDEHYDE CONDENSATE AND A PARTIALLYPOLYMERIZED, WATER-SOLUBLE BISULFITE-MODIFIED THIOUREA-FORMALDEHYDECONDENSATE CONTAINING IN 100 PARTS BY WEIGHT OF THE BLEND 55 TO 88 PARTSOF THE FORMER AND 45 TO 20 PARTS OF THE LATTER, SAID ALKYLATEDUREA-ALDEHYDE COMPONENT BEING PREPARED BY REACTING IN AQUEOUS MEDIUMRELATIVE PROPORTIONS OF 1.50 TO 2.25 MOLES OF A WATER-SOLUBLE ALIPHATICALDEHYDE WITH 1 MOLE OF UREA AT A PH OF FROM 7.0 TO 10.0 AND AT ATEMPERATURE OF FROM 70 TO 100*C. FOR FROM .25 TO 2.0 HOURS, ADJUSTINGTHE PH OF THE REACTION MIXTURE TO A PH OF BETWEEN 4.0 AND 6.0, ANDREACTING SAID UREA-ALDEHYDE CONDENSATE AT A TEMPERATURE OF 70 TO 100*C.FOR FROM .25 TO 2.0 HOURS, WITH 0.3 TO 2.0 MOLES OF AN ALIPHATIC ALCOHOLCONTAINING FROM 1 TO 3 CARBON ATOMS, AND THEREAFTER NEUTRALIZING THEREACTION MIXTURE, SAID BISULFITE-MODIFIED THIOUREA COMPONENT BEINGPREPARED BY REACTING IN AQUEOUS MEDIUM RELATIVE PROPORTIONS OF 0.4 TO1.4 MOLES OF FORMALDEHYDE, .01 TO .06 MOLE OF A MATERIAL SELECTED FROMTHE GROUP CONSISTING OF WATER-SOLUBLE BISULFITE AND SULFITES CAPABLE OFYIELDING SUCH BISULFITE UNDER THE CONDITIONS TO BE DESCRIBED AND 1 MOLEOF THIOUREA, AT A PH RANGE OF FROM 7.0 TO 10.0 AND A TEMPERATURE OF FROMBETWEEN 50 AND 100*C. FOR FROM 1 TO 30 MINUTES, AND THEREAFTER BLENDINGTHESE RESPECTIVE COMPONENTS IN THE WEIGHT RATIO SET FORTH ABOVE.